In many cases it is advantageous to securely and permanently connect metal sheet members with plastic members.
Many prior art publications teach, in that respect, the use of pins or screws inserted into cavities in the members that are coupled.
U.S. Pat. No. 6,213,328 refers to a method of coupling a metal sheet to a plastic member formed with sheet receiving grooves. According to U.S. Pat. No. 6,213,328, projections are provided on the surface of the metal sheet, each remaining integrally connected to the metal sheet, and each protruding from the surface thereof and featuring at least one sharp edge. The metal sheet is then inserted into the sheet receiving groove, and engaging the sharp edge to resist retracting the metal sheet from the groove.